D&D 5E Never Give Them Unlimited Black Powder

[Bacon Bits]

A barrel of gunpowder will not do 20d6 points of damage.

The problem is not that it's enough gunpowder. It's the barrel. Black powder is a low explosive. if you put a pile of it on the ground and ignite and it will... burn. What makes it go boom is the increased pressure which keeps increasing until the container explodes. So the barrel is what explodes, and it will burst fairly quickly. I would guestimate in the 4d6 range?

Being a low explosive matters a lot less than you think. For example, think how easily a cannonball or musketball is rammed into a gun barrel. There isn't a huge amount of resistance there, but it creates a tremendous amount of destruction without needing high explosives to do it.

There's many examples of catastrophic gunpowder explosions in history, too.

There was a magazine explosion at the Siege of Almeida.

When the French bombardment opened on August 26 at 6 AM, several quarters of the town were quickly set on fire, and the defending guns of the nearest three batteries overwhelmed. However, the defences held. The governor was confident in withstanding the assault, until a shell made a freak hit. The great magazine in the castle had been used through the day to supply the defenders, and at some point a leaky powder keg had left a trail of powder leading up to the courtyard. At around 7 PM, one French shell landed in the courtyard, igniting a gunpowder trail that led through the still open door, and set off a chain reaction into the magazine. The ensuing explosion killed 600 defenders and wounded 300 more. The castle that housed the gunpowder was razed and sections of the defenses were damaged, leaving a crater still visible today.

It's very unlikely that gunpowder of this era was stored in anything other than wooden barrels or kegs.

At the Battle of Torrington in 1646, an explosion of gunpowder explicitly recorded as being within barrels occurred:

The fighting at the barricades lasted two hours at push of pike. At last the Cornish infantry gave way and retreated into the town, where bitter fighting continued. A stray spark ignited the Royalist magazine in Torrington church, where eighty barrels of gunpowder were stored. The explosion destroyed the church, killed all the prisoners held there and narrowly missed killing Fairfax.

See also:

Destruction of the Parthenon, 1687. Yes, that Parthenon. It was much more intact until stored gunpowder within it exploded and "...three of the sanctuary’s four walls nearly collapsed and three-fifths of the sculptures from the frieze fell. Nothing of the roof apparently remained in place. Six columns from the south side fell, eight from the north, as well as whatever remained from eastern porch, except for one column. The columns brought down with them the enormous marble architraves, triglyphs and metopes."

Indeed, virtually all of the largest artificial non-nuclear explosions prior to WWI were caused by explosions of gunpowder, many of them resulting in catastrophic damage and loss of life. All of these would have been a low explosive gunpowder of one flavor or another, almost certainly stored in wooden barrels, casks, or kegs.

There have even been theoretical reproductions of the explosion that would of resulted from the Gunpowder Plot in 1605:


Point being that it's really not difficult to make a extraordinarily powerful explosion with gunpowder stored in barrels.

 

[MarkB]

There was a magazine explosion at the Siege of Almeida.

When the French bombardment opened on August 26 at 6 AM, several quarters of the town were quickly set on fire, and the defending guns of the nearest three batteries overwhelmed. However, the defences held. The governor was confident in withstanding the assault, until a shell made a freak hit. The great magazine in the castle had been used through the day to supply the defenders, and at some point a leaky powder keg had left a trail of powder leading up to the courtyard. At around 7 PM, one French shell landed in the courtyard, igniting a gunpowder trail that led through the still open door, and set off a chain reaction into the magazine. The ensuing explosion killed 600 defenders and wounded 300 more. The castle that housed the gunpowder was razed and sections of the defenses were damaged, leaving a crater still visible today.

It's very unlikely that gunpowder of this era was stored in anything other than wooden barrels or kegs.

But all of those barrels and kegs would have been stored inside a relatively small stone-walled chamber, and that would then have become the pressure vessel for the explosion. The entire chamber would have fragmented and showered the area with masonry shrapnel, and if any part of it was a supporting wall for the rest of the fortification, the secondary structural damage could have been extreme.

The same number of kegs and barrels out in an open field wouldn't cause nearly as great an explosion - but would also be much easier to be hit by a stray shot.

 

[LordEntrails]

Not in 20 years or more. There is a reason the Decanter of Endless water no longer is Endless!

 

[LordEntrails]

Not that I've ever heard of. Citation needed.

Here you go;

 

[Aelryinth]

Here you go;

For shame! It obviously collapsed under its own weight from a small pop. Stop bringing movie physics into my gaming fantasy!

On a side note, I think he rolled 20d6 and did at least 10 points of structural damage.

 

[Aelryinth]

But all of those barrels and kegs would have been stored inside a relatively small stone-walled chamber, and that would then have become the pressure vessel for the explosion. The entire chamber would have fragmented and showered the area with masonry shrapnel, and if any part of it was a supporting wall for the rest of the fortification, the secondary structural damage could have been extreme.

The same number of kegs and barrels out in an open field wouldn't cause nearly as great an explosion - but would also be much easier to be hit by a stray shot.

Dude, you're talking about pressure vehicles and explosion dispersion in a world where if you stand one inch outside a fireball you take no damage whatsoever, but full damage if you ARE inside that one inch, and the second after the fireball is gone, ambient temperature is back to normal. Unless something got lit on fire, it's cool to the touch!

 

[MarkB]

For shame! It obviously collapsed under its own weight from a small pop. Stop bringing movie physics into my gaming fantasy!

On a side note, I think he rolled 20d6 and did at least 10 points of structural damage.

Yeah, but he also used several specially-designed explosive devices packed into an enclosed space. Not just a barrel.

Dude, you're talking about pressure vehicles and explosion dispersion in a world where if you stand one inch outside a fireball you take no damage whatsoever, but full damage if you ARE inside that one inch, and the second after the fireball is gone, ambient temperature is back to normal. Unless something got lit on fire, it's cool to the touch!

No, in that response I was talking about an actual real-world example.

 

[Aelryinth]

Yeah, but he also used several specially-designed explosive devices packed into an enclosed space. Not just a barrel.


No, in that response I was talking about an actual real-world example.

Dude, he had a cauldron of gunpowder. One.

 

[Don Durito]

Unlimited? No. Magic items have expensive costs, treasure is limited, and magic can be controlled (Dispel Magic, Antimagic Field, etc). On occasion I hear about someone destroying the economy because they used some spell combo to turn dirt into gold or something though. (Hasn't happened in any game I've been in.) One time my PCs tried to turn a magic orb that could use Gust of Wind at will into a perpetual motion machine, and even that wasn't broken because it was intelligent, there was only one of it, and it had a downside (could drive people insane just by talking to it).

Even Eberron doesn't have "unlimited magic" with its Dragonmarked powered magic items (there aren't that many member of House X).

Well yes. But you're not practically going to have unlimited black powder either. There's only so much that can be carried around.

And woe betide any party that has a wagon full of gunpowder they're carrying with them. One fireball and...

 

[Aelryinth]

Well yes. But you're not practically going to have unlimited black powder either. There's only so much that can be carried around.

And woe betide any party that has a wagon full of gunpowder they're carrying with them. One fireball and...

It doesn't have to be unlimited, you know. It has to be enough to destroy their enemies. There is a HUGE difference there, especially with storage/shrinking magic.